


Research

by Have



Category: Undertale (Video Game)
Genre: ...except it's SwapFell Sans, Alternate Universe - Swapfell (Undertale), Clinical terminology, Dump-Diving!Dadster, Headcanons concerning disparate biology., Maybe a bit too far ahead., Other, Pining, Reader doesn't actually appear in this fic..., Reader is human., Reader may or may not be River Person, Swapfell, Swapfell Sans (Undertale), fellswap, so instead of just pining away he's going to plan ahead.
Language: English
Status: Completed
Published: 2018-11-02
Updated: 2018-11-02
Packaged: 2019-08-09 18:00:56
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,002
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16454741
Author URL: https://archiveofourown.org/users/Have/pseuds/Have
Summary: A Dating Manual? Sans flipped through the pages briefly, stopping on one when he caught the words "Dating HUD". Do humans use those?A handbook with a tattered cover (clearly salvaged from the Dump) that appeared to be of...what? Dominance and submission? Hm...Sans set that one aside as well, planning to return later with a notebook and pen.A book by one of the queen's scouts titled "Subtext and Socialization: An Analysis of Human Courting Rituals" ... Perhaps he should take this one, instead?





	Research

**Author's Note:**

  * Inspired by [Everything Will Be All Right](https://archiveofourown.org/works/8131136) by [Mortals_Lust4_CupOSin](https://archiveofourown.org/users/Mortals_Lust4_CupOSin/pseuds/Mortals_Lust4_CupOSin). 



> [This fic was edited on March 13, 2019.
> 
> Many thanks to my editor, Lady_Arkytior_of_Dunans, who is a fantastic author and a master at comprehensive world-building in fics.
> 
> (Her AO3 is here: archiveofourown.org/users/Lady_Arkytior_of_Dunans/pseuds/Lady_Arkytior_of_Dunans  
> and her tumblr here: ladyarkytiorofdunans.tumblr.com/)]

Sans was almost disappointed. No, he was definitely disappointed.

WingDings, of all monsters, ought to have better security. There were few willing to risk the wrath of a Gaster for musty books and scavenged trinkets, but fascination with human media had spread like wildfire in recent years. Sans couldn't help but scowl at the thought (however hypothetical) of his father allowing himself to be robbed by short-sighted fanatics. Well...robbed by someone other than himself, that is.

Perhaps it wasn't fair to just shortcut past the exterior of WingDings's shop, but honestly, who in their right mind doesn't at least plant a few traps inside to deter shoplifters?

Regardless, Sans still had to find what he needed and get out, and he was going to take advantage of the situation.

Fifteen minutes. That's how long he knew for certain that he had until that old bag of bones returned from scouring the Dump for any new human oddities. If there's something interesting to find...if someone distracts him...that might give Sans a little more leeway. But there's no way of knowing for sure, and he was already planning to take less than ten, anyways (not a single trap? Really?).

The shop was a testament to WingDings's somewhat morbid sense of curiosity with the very species that sealed their kingdom beneath the earth. Scattered about in what Undyne might call "organized chaos" were various mementos of a position the eldest skeleton turned his back on long before Sans could remember and hoarded junk that who-knows-how-many humans had the sense to discard even if WingDings didn't. And books. So many, many books.

...Maybe the fixation was hereditary. Not so long ago, Sans would've sworn it wasn't.

But now he was on his knees, digging through piles of old books and placing them neatly to the side in an attempt to remember how they were arranged before he started his search. It occurred to Sans that while the piles were sloppily stacked in a way that barely avoided the need for gravity magic, they did have a sort of order to them. Old legends and fantastic tales of what humans might have remembered or imagined about monsters under the table. Texts on various animals living aboveground by the lamp. Neuroscience and psychology by WingDings's desk. And beside the door separating his shop from his actual home...

A Dating Manual? Sans flipped through the pages briefly, stopping on one when he caught the words "Dating HUD". Do humans use those? It's considered rather old-fashioned, here in the Underground, but...

He scowled to himself before pointedly setting the manual aside. The more he took, the more likely WingDings would notice the theft. What he had in mind was risky enough...

The next book in the pile was...really more of a booklet. It was a handbook with a tattered cover (clearly salvaged from the Dump) that appeared to be of...what? Dominance and submission? Hm...

Sans set that one aside as well, planning to return later with a notebook and pen.

Then he found a book that must have been by one of the queen's less single-minded scouts titled "Subtext and Socialization: An Analysis of Human Courting Rituals" ... Perhaps he should take this one, instead?

No, no. He could only afford to take one. If WingDings discovered that anything was missing or changed his routine (as unlikely as that was) Sans would be unable to get the book he truly needed! He was certain there were other resources concerning how to woo or ravish humans, but the information he came for...that's something very few alive would know anything about. And he wasn't about to ask the bony bastard for a synopsis.

Finally Sans came upon an old, pre-War text. Its cover was worn from age, unlike the small BDSM book's water damage. Its spine was still firm, but the edges were frayed and the letters faded. Too faded to read. Sans's grip was gentle, uncertain of the structural integrity of the book as he opened to the title page.

Aha! "Human Reproduction and the Conception of Hybrids", precisely what he needed!

The War was so long ago, and history books never really spoke of humans beyond their ruthlessness. Hopefully, the information here had a basis in reality instead of mere theory...

He cautiously turned the pages, satisfied to see they were in far better condition than the cover. After a moment he realized they were made of cotton instead of wood pulp. It must be even older than he thought. Once he felt confident that flipping through them with his thumb wouldn't cause them to disintegrate, he quickly found a chapter on pregnancy:

"The human form is composed of condensed physical matter—largely water-based—and while said matter grows and heals similar to monster anatomy, it does so with far less direct input from the SOUL. Perhaps the excess of Determination provides an innate impulse to survive regardless of HOPE or—"

Sans forced his eyelights to skim past the next few paragraphs. He'd go back to that later. Aha! There it is!

"While it is possible for any human to reproduce with a monster mate—so long as a SOUL bond has been fully established and the intent to breed confirmed—the physical formation of the fetus is a complex process requiring a meticulous and conscious blend of magic and Determination. So long as the proper intent is provided, gestation within a human womb has been discovered to provide direct access to the materials necessary for a physical form to develop even as the magic which would form the SOUL continues to coalesce. Monster wombs are also viable, but the SOUL would develop at a quicker rate than the physical form and the relative abundance of Determination carries certain risks if not carefully monitored."

A large, genuine grin grew on Sans's face as he read, crinkling his eye sockets at the corners before shifting into his trademarked sharp and wicked rictus.

He could hardly wait~

**Author's Note:**

> I have a tumblr for fandom theories and ideas: noplotnostory.tumblr.com  
> [Edit: I also have a pillowfort, now! (pillowfort.io/noplotnostory)]
> 
> Please let me know if you see any typos or mistakes!


End file.
